A long slide fastener chain can have a fly strip sewn to one stringer tape and chain of coupled-together rows of fastener members, the chain being subdivided by gaps into portions corresponding to subsequent slide fasteners (see U.S. Pat. No. 1,495,686).
On a first side of the chain an opening or spreading device is provided for opening up the chain and uncoupling the fastener member rows near the opening or spreading device. The device can have two opening lever arms which are movable oppositely to one another, are spring-biased towards one another and have abutments and an opener or spreader adapted to drop in between the opening lever arms.
On the second side of the chain a slider manipulator is provided to receive a slider and to pivot the same into the gap. A delivery device is disposed downstream of the opening or spreading device and the slider manipulator in the direction of movement of the stringer and has two driven rollers. The driven rollers are associated with the stringers and are connectable non-positively thereto. The slider is attachable by way of its core end to the uncoupled closure members by a movement of the slider in the opposite direction to the movement of the chain.
A slider has a bottom part and a top part interconnected by way of a core disposed at one end of the slider. The two fastener member rows project uncoupled from such end in the case of an attached slider. At the opposite end of the slider, also known as the slider mouth, the closure member rows extend coupled together from the slider. Also, the slider is formed on both sides with stringer-guiding slots enabling the stringers to extend through the slider. Each of the two rows of fastener members of the slide fastener chain has a stringer.
In one particular form of a slide fastener chain a fly strip, as noted, for example of cloth, is sewn to a stringer. The fly strip is comparatively wide, usually projects on one side beyond the stringer to which it is sewn and overlaps the closure member rows on the other side. A fly strip facilitates the attachment of a finished slide fastener to a garment.
A device for folding the fly strip which can expose the closure member rows covered thereby must therefore of course be disposed upstream of an apparatus for attaching a slider to a long slide fastener chain having a fly strip.
The word "gap" denotes a region of a long slide fastener chain where a predetermined number of closure members are missing from both stringers, so that inside free stringer edges, possibly in the form of edge beads or edge bead threads, are exposed.
In an opening or spreading device having two spreading lever arms and a spreader or opener the spreading levers and/or the opener have actuating surfaces lever arms, press the same apart from one another. The spreading lever arm abutments which have dropped into a gap spread or open the stringers on the inside free stringer edges of the gap and uncouple a few closure members near the opening or spreading device.
A slider manipulator can be, for example, of substantially drum-shaped construction, in which event it has a rotational axis extending transversely to the length of the slide fastener chain. During a rotation of the manipulator a slider can be received, for example, from a rail of a slider feeder.
As a rule, the top part of the slider points towards the rotational axis and the slider can be retained and released by means of a controllable finger. During further rotation of the manipulator the slider is pivoted into the opened gap, drawn on to the uncoupled closure members and released from the manipulator. Basically, further means can be provided near the manipulator to attach a leader to the chain after attachment of the slider, to sever the tapes in the gap and/or to attach end members. A finished slide fastener can therefore be produced from a long slide fastener chain in a single movement cycle.
The apparatus of U.S. Pat. No. 4,495,686 has an opener or spreader which remains in its dropped position after it has dropped in between the spreading lever arms, so that the stringers continue to remain wide open during the attachment of the slider. The spacing between the inside free stringer edges is only slightly less than the width of the slider to be attached. When the slider pivots into the gap the inside free stringer edges are threaded in automatically by the stringers which are subjected to tension near the gap by means of the delivery device. This is the most critical step in the attachment of the slider.
A disadvantage of the known apparatus is that during this step the inside free stringer edges are opened very wide, there is no active guidance of the slider during the threading of the inside free stringer edges into the stringer-guiding slots and the inside free stringer edges cannot themselves be maintained in tension. Malfunctioning in the threading of the inside free stringer edges into the stringer-guiding slots in the slider may therefore occur which may be very disturbing and cause an interruption in continuous production. Another disadvantage is the continuous wide opening which occurs even in a satisfactory threading-in operation of the inside free stringer edges since the uncoupled closure member rows tend to twist and therefore to jam during the remainder of the slider attachment step.